Dr. Foville on the Anatomy of the Brain. 25 



and the internal and external margins of the orbital region, 

 are in exclusive relation with the prolongations of the pyra- 

 midal fasciculus of the crus. 



All the convolutions developed between the border, pro- 

 perly speaking, and the great circumference of the hemi- 

 sphere, pertain to the fibrous emanations from the perforated 

 quadrangle. 



All the convolutions of the insula situated between the 

 short region of the border which is traversed by the external 

 root of the olfactory nerve, and the convolutionary inclosure 

 of the fissure of Sylvius, belong peculiarly to the fibrous parts 

 emanating from that region of the border to which belongs 

 the external root of the olfactory nerve. Lastly, the great 

 circumference in which are found the external surface of the 

 convolutions belonging in particular to the terminations of 

 the pyramidal fasciculus of the crus, and the internal surface 

 of those which belong exclusively to the fibrous emanations 

 from the perforated quadrangle, is destined by its double re- 

 lations to a mixed purpose. It contains the anastomosis of 

 the fibrous extremities of the pyramids and of the fibrous ex- 

 tremities issuing from the perforated quadrangle. 



The convolutionary inclosure of the fissure of Sylvius, to 

 the extra fissural margin of which are connected the convolu- 

 tions developed upon the pyramidal termination of the crus, 

 and with the fissural edge of which is combined the fibrous 

 duplicature of the convolutions of the insula proceeding from 

 that part of the border to which belongs the external root of the 

 olfactory nerve, is destined, like the line of convolution which 

 courses along the great circumference of the hemisphere, to 

 contain the anastomosis of the fibrous parts belonging to the 

 pyramidal convolutions with those which proceed from the 

 border. They are thus in relation with the sensorial nerves 

 of the brain, with the posterior parts of the crura, and with 

 the medulla oblongata. 



We might proceed to describe the various groups formed 

 by the two orders of convolutions which we have now esta- 

 blished; but it must not be forgotten that our present object 

 is merely to give a succinct idea of the principal results of 

 our anatomical investigations. 



But I have as yet only pointed out a very trifling portion 

 of the fibrous layers intermediate between the nerves of sen- 

 sation of the brain, and I shall immediately proceed to men- 

 tion the other parts which unite with the fibrous band and 

 the superficial quadrangle previously described. Each of 

 these parts forms, like the preceding, a circle which traverses 

 the inferior part of the crus cerebri, some embracing this part 



